DOI: 10.1063/1.1656743 ISSN:
Effect of ac Impedance on dc Voltage-Current Characteristics of Superconductor Weak-Link Junctions
D. E. McCumber- General Physics and Astronomy
Because the Josephson pair current in a weak-link superconductor junction is a nonlinear parametric function of junction voltage, the ac impedance seen by the junction influences both the response time to changes in bias and the dc voltage-current characteristics. The first effect is obvious; the second, considered here, has not been generally recognized. Both are relevant to device design. Two special cases which illustrate the basic principles involved are worked out in detail; they correspond, respectively, to ac capacitive and inductive loading. The results partly explain differences in the dc voltage-current characteristics of plane-parallel and point-contact junctions.